# Periodic function

1. Oct 10, 2007

### Ljilja

Hi all,
I am new to this forum.
My question is:
Find values of b and r for which trajectories are attracted to a periodic trajectory.
The function is:
f(x) = r*x/(1+x)^b

No proofs needed, just a numerical demonstration.

Thanks a lot,
Ljilja

2. Oct 10, 2007

### Hootenanny

Staff Emeritus
Hiya Ljilja and welcome to the forums,

For future reference we have dedicated homework forums for such questions. In addition, according to the forum guidelines you are required to show some sort of effort in solving the problem yourself.

3. Oct 10, 2007

### J77

I also presume that the whole question hasn't been stated; ie. the word trajectory (to me) implies a differential equation $$\dot{x}=f(x)$$